I wouldn't dignify what I'm doing as 'study'; it was just an interesting chart; the google public data thing is neat, I think it's their attempt at making sure they don't get outdone by Wolfram Alpha. Both the Google Public Data and Wolfram Alpha seem to be pretty brittle though, if you want to answer questions outside what the designers / curators had in mind both tend to fail abruptly. There's no robust 'search' for answering data mining questions...yet.